混合模式色谱中的协同保留机理研究

发布时间：2024-03-27 20:10

　　高效液相色谱(HPLC)作为现代分析化学中最重要的一种分离分析技术,在化学、生物、医药和环境科学等领域得到了广泛应用。近年来,单模式色谱以其高灵敏度、高选择性和高分离能力等特点得到了快速发展,但是,在分离复杂样品过程中常存在一定的局限性。例如,反相色谱(RPLC)是最常用的色谱模式,对疏水性物质具有较强的选择性和灵敏度,但对强极性和离子型化合物的保留较弱,而且在分离碱性化合物时常导致峰形拖尾、柱效和重复性变差;离子交换色谱(IEC)常用于分离可解离的或离子型的化合物,但对于带相同电荷而疏水部分有差异的化合物分离度较差。离子对色谱(IPC)克服了以上困难,通过在流动相中加入离子对试剂,增加了离子型化合物在反相色谱中的保留,能够同时分离中性和离子型化合物。然而离子对试剂的引入造成柱平衡时间较长,与质谱不兼容等缺陷,不适用于梯度洗脱和制备纯化,从而限制了IPC在分离分析中的广泛应用。混合模式色谱(MMC)依据固定相与溶质的多种作用机理,能够在单一色谱柱上实现不同的分离模式,而且在混合模式条件下可同时进行多种类型样品的分离检测。这种无离子对试剂参与的固定相设计能够节约成本、提高工作效率。相比于...

【文章页数】：113 页

【学位级别】：硕士

【文章目录】：
摘要
ABSTRACT
Chapter1 Literature Review
    Introduction
    1.1 High Performance Liquid Chromatography
        1.1.1 Principle and Instrument
        1.1.2 Operation Modes
        1.1.3 HPLC Packings
    1.2 Mixed-Mode Chromatography
        1.2.1 RPLC/IEC
        1.2.2 RPLC/HILIC
        1.2.3 HILIC/IEC
        1.2.4 Trimodal Stationary Phase
    1.3 Preparation of Mixed-Mode Stationary Phase
        1.3.1 Chemical Bonding
        1.3.2 Atom Transfer Radical Polymerization
        1.3.3 Click Chemistry
    1.4 Retention Mechanism in Mixed-Mode Chromatography
        1.4.1 Retention Models
        1.4.2 Cooperative Effect
    1.5 Goals and Objectives
Chapter2 Experimental Section
    2.1 Reagents and Instruments
        2.1.1 Reagents
        2.1.2 Materials and Instruments
    2.2.Preparation and Characterization of RP/IEX Stationary Phases
        2.2.1 Preparation of RP/IEX Stationary Phases
        2.2.2 Characterization of RP/SAX Stationary Phases
        2.2.3 Characterization of RP/SCX Stationary Phases
        2.2.4 Application of Mixed-Ligand RP/SCX Stationary Phase
    2.3 Study of Retention Mechanism in Mixed-Mode Chromatography
        2.3.1 Separation of Basic Drugs
        2.3.2 Influence of pH
        2.3.3 Influence of Ionic Strength
        2.3.4 Influence of Solvent Strength
    2.4 Assessing the Contribution of Chelate Cooperativity in Mixed-Mode Chromatography
        2.4.1 Separation of Alkylanilines on RP/SCX Stationary Phases
        2.4.2 Separation of Alkylbenzoic Acids on RP/SAX Stationary Phase
        2.4.3 Separation of Alkylbenzenes on RP/IEX Stationary Phases
Chapter3 Preparation and Characterization of RP/IEX Stationary Phases
    Introduction
    3.1 Preparation and Characterization of RP/SAX Stationary Phases
        3.1.1 Elemental Analysis
        3.1.2 Chromatographic Evaluation
    3.2 Preparation and Characterization of RP/SCX Stationary Phases
        3.2.1 Solid-State¹³C NMR
        3.2.2 Elemental Analysis
        3.2.3 Chromatographic Evaluation
    3.3 Application
        3.3.1 Separation of Melbine and Impurities
        3.3.2 Simultaneous Separation of Acidic,Neutral and Basic Drugs
    3.4 Summary
Chapter4 Study of Retention Mechanisms in Mixed-Mode Chromatography
    Introduction
    4.1 Separation of Basic Drugs on RP/SCX Stationary Phases
    4.2 Influence of pH
    4.3 Influence of Ionic Strength
        4.3.1 Analysis of Retention Mechanism Models
        4.3.2 Quantitative Evaluation of Individual Interactions
        4.3.3 Relationship Between Intercept and Slope for k_T-1/C Plots
    4.4 Influence of Solvent Strength
    4.5 Summary
Chapter5 Assessing the Contribution of Chelate Cooperativity in Mixed-Mode Chromatography
    Introduction
    5.1 Theoretical Model
    5.2 Determination of the Reversed-Phase Retention
    5.3 Determination of the Ion-Exchange Retention
    5.4 Determination of Chelate Cooperativity
    5.5 Relationship Between Intercept and Slope for k_T-1/C Plots
    5.6 Summary
Chapter6 Conclusions and Outlooks
    6.1 Conclusions
    6.2 Outlooks
References
Notes on Publications and Participation in Scientific Research
Acknowledgements



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